Hi
I made a small lab to test this and I think this may help you about your questions
# Lab example
EIGRP used between routers to have access to their loopbacks
/// R1
interface Loopback0
ip address 1.1.1.1 255.255.255.255
!
interface FastEthernet0/0
ip address 10.1.12.1 255.255.255.0
...
vrrp 1 ip 10.1.12.3
vrrp 1 priority 120
!
ntp master 1
!
/// R2
interface Loopback0
ip address 2.2.2.2 255.255.255.255
!
interface FastEthernet0/0
ip address 10.1.12.2 255.255.255.0
...
vrrp 1 ip 10.1.12.3
!
ntp server 1.1.1.1
/// R3
interface FastEthernet0/0
ip address 10.1.12.100 255.255.255.0
!
ntp server 10.1.12.3
!
/// Verifications from R3
From R3 we can ping VIP address and we are able to set the VIP as ntp server
R3#ping 10.1.12.3
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.1.12.3, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 16/20/24 ms
R3#
R3#conf t
Enter configuration commands, one per line. End with CNTL/Z.
R3(config)#ntp server 10.1.12.3
R3(config)#end
R3#
R3#show ntp status
Clock is synchronized, stratum 2, reference is 10.1.12.3
nominal freq is 250.0000 Hz, actual freq is 250.0000 Hz, precision is 2**16
ntp uptime is 1100 (1/100 of seconds), resolution is 4000
reference time is C0294827.CFE78FBE (00:21:59.812 UTC Fri Mar 1 2002)
clock offset is -23.9935 msec, root delay is 23.99 msec
root dispersion is 3977.54 msec, peer dispersion is 3937.52 msec
loopfilter state is 'CTRL' (Normal Controlled Loop), drift is 0.000000000 s/s
system poll interval is 64, last update was 1 sec ago.
R3#
/// Verifications from R1 and R2 (VRRP)
R1#show vrrp
FastEthernet0/0 - Group 1
State is Master
Virtual IP address is 10.1.12.3
Virtual MAC address is 0000.5e00.0101
Advertisement interval is 1.000 sec
Preemption enabled
Priority is 120
Master Router is 10.1.12.1 (local), priority is 120
Master Advertisement interval is 1.000 sec
Master Down interval is 3.531 sec
R1#
R2#show vrrp
FastEthernet0/0 - Group 1
State is Backup
Virtual IP address is 10.1.12.3
Virtual MAC address is 0000.5e00.0101
Advertisement interval is 1.000 sec
Preemption enabled
Priority is 100
Master Router is 10.1.12.1, priority is 120
Master Advertisement interval is 1.000 sec
Master Down interval is 3.609 sec (expires in 3.509 sec)
R2#
/// Verifications from R1 and R2 (NTP)
R1#show ntp status
Clock is synchronized, stratum 1, reference is .LOCL.
nominal freq is 250.0000 Hz, actual freq is 250.0000 Hz, precision is 2**18
reference time is C029485C.384E8DA8 (00:22:52.219 UTC Fri Mar 1 2002)
clock offset is 0.0000 msec, root delay is 0.00 msec
root dispersion is 0.02 msec, peer dispersion is 0.02 msec
R1#
R2#show ntp status
Clock is synchronized, stratum 2, reference is 1.1.1.1
nominal freq is 250.0000 Hz, actual freq is 250.0000 Hz, precision is 2**16
ntp uptime is 135900 (1/100 of seconds), resolution is 4000
reference time is C0294775.97D95CFA (00:19:01.593 UTC Fri Mar 1 2002)
clock offset is -5038.2055 msec, root delay is 7.86 msec
root dispersion is 8556.47 msec, peer dispersion is 4.86 msec
loopfilter state is 'SPIK' (Spike), drift is -0.000000000 s/s
system poll interval is 64, last update was 303 sec ago.
R2#
####### Redundancy forcing a switching in vrrp making R2 primary
R1#conf t
Enter configuration commands, one per line. End with CNTL/Z.
R1(config)#interface FastEthernet0/0
R1(config-if)# vrrp 1 priority 80
R1(config-if)#end
R1#
Mar 1 00:25:22.415: %VRRP-6-STATECHANGE: Fa0/0 Grp 1 state Master -> Backup
R1#
R1#show vrrp
FastEthernet0/0 - Group 1
State is Backup
Virtual IP address is 10.1.12.3
Virtual MAC address is 0000.5e00.0101
Advertisement interval is 1.000 sec
Preemption enabled
Priority is 80
Master Router is 10.1.12.2, priority is 100
Master Advertisement interval is 1.000 sec
Master Down interval is 3.687 sec (expires in 3.151 sec)
R1#
R3 is still synchronized
R3#show ntp status
Clock is unsynchronized, stratum 3, reference is 10.1.12.3
nominal freq is 250.0000 Hz, actual freq is 250.0000 Hz, precision is 2**16
ntp uptime is 83300 (1/100 of seconds), resolution is 4000
reference time is C0294B23.C9A069CD (00:34:43.787 UTC Fri Mar 1 2002)
clock offset is -986.6018 msec, root delay is 17.08 msec
root dispersion is 8944.68 msec, peer dispersion is 0.99 msec
loopfilter state is 'SPIK' (Spike), drift is 0.000000000 s/s
system poll interval is 64, last update was 59 sec ago.
R3#
I hope this information be usefull for you
BR
Gaston
